1. Suppose the prices of 0.31 percent of stocks fell today compared to their beginning prices. Assume each stock behaves independently. You randomly check one stock at a time until you find one that had a price drop. What is the probability that you have to examine more than 6 stocks before finding one with a price drop?
2. Suppose that a veteran software engineer makes an average of 4.08 coding errors per 10000 code lines. What is the probability that a random selection of 2500 code lines has no errors in it?
3. Suppose that a veteran software engineer makes an average of 6.8 coding errors per 10000 code lines. What is the probability that a random selection of 2500 code lines has at most 3 typos in it?